Improvement of Astaxanthin Production in Coelastrum sp. by Optimization Using Taguchi Method

Background and Objective: Astaxanthin is a keto-carotenoid pigment known as one of the most valuable compounds with great potentials in the market. It has widely been used in nutraceutical, pharmaceutical, cosmetics and food industries due to its strong antioxidant activity. Green microalgae seem as promising natural sources in production of astaxanthin. The aim of this study was to optimize astaxanthin production in Coelastrum sp. to overcome low productivity of microalgae. Materials and Methods: This study was carried out using experimentally statistical technique and Taguchi method to find optimum conditions for maximizing production of astaxanthin in green microalgae, Coelastrum sp. Effects of nutritional (carbon and nitrogen) and environmental (light and salinity) factors on biomass and astaxanthin production were investigated. Experiments were carried out for light intensity (250-550 μmol photons m^-2 s^-1), salinity using sodium chloride (1.0-3.0 g l^-1), carbon source using sodium acetate (0.5-2.0 g l^-1) and nitrogen source using sodium nitrate (0.1-0.3 g l^-1). Results and Conclusion: Results showed that optimum conditions of astaxanthin production in Coelastrum sp. included 250 μmol photons m-2 s^-1 of light intensity, 3 g l^-1 salinity, 0.5 g l^-1 carbon and 0.1 g l^-1 nitrogen with a maximum yield of astaxanthin (14.44 mg l^-1), which was 2-fold higher than that before optimization. This optimization resulted in high quantities of astaxanthin production using optimization of conditions that affected production yields of astaxanthin from Coelastrum sp.